The currently available bicycles are designed for pedaling with less effort, carrying about conveniently, and occupying less space to meet the demands in exercise and leisure activities, and are therefore particularly welcome by office workers who are too busy to have no time to take exercise. However, it is not safe to ride a bicycle in the night or at a dark place. Thus, there have been developed light-emitting elements or reflective units as a warning device for bicycles to reduce accidents while beautify the bicycles.
Taiwanese invention patent application No. 092214918 entitled “Warning Device for Bicycle” filed by the same applicant on Aug. 18, 2003 discloses a warning device that includes a fixed mechanism (11) with magnets (12) being fixedly mounted on a bicycle frame (22), and a fixing plate (13) fixedly mounted on a wheel rim (21). A coil (14) is screwed to the fixing plate (13) using screwing elements (16) made of a soft steel material. When the wheel rim (21) rotates, the coil (14) is brought to pass the magnets (12) and electromagnetically induced to produce induction current for driving light-emitting elements (18) to emit light.
In brief, the warning device for bicycle disclosed in the above-mentioned Taiwanese invention patent application utilizes the electromagnetic induction of the coil on the fixing plate (13) mounted on the rotating wheel rim by the magnets (12) of the fixed mechanism (11) fixedly mounted on the bicycle frame (22) to produce induced current for driving light-emitting elements (18).
Although the above-structured warning device for bicycle provides good warning function and could be easily assembled to and disassembled from the bicycle to attract consumers and enable reduced packing and transporting costs, it is still desired to develop a further improved warning device for bicycle.